function showDescription(elem, fileId) {

    var jsonRequest = new Request.HTML({ url: "ajaxservice.aspx?action=getFile2&id=" + fileId + "&d=" + new Date().getMilliseconds(), onComplete: function(responseTree, responseElements, responseHTML, responseJavaScript) {

        var popup = new mooPopup({ dockelem: elem, peakmode: 'ro', headline: "Detail", width: 500, content: responseHTML, ydelta: -40, xdelta: -4 });

    }
    }).get();
}